High Sensitivity Speakers that work best with SS

I currently use a Bryston 4BSST amp which is 300wpc into 8 Ohms, 500wpc in 4 Ohms. My JBL S4700s have sensitivity of 94db. It's a good combo to my ears. I'm guessing that JBL being under the ownership of Harman, were voiced using Levinson amps. Levinson amps are high powered too. I prefer Bryston soundwise. But that another discussion there. Anyway, the combo works well, and I'd like to try lower powered Class A solid state and perhaps even tube amps. But I'm not really in any hurry to do so...haste makes waste especially in audio!

NVP,
Your thought process is on the right track.The motivation for Nelson Pass`s First Watt line of amplifiers was high quality sound at low power levels.He recognizes that higher efficiency speakers require 'quality' more so than power quantity.These speakers at normal listening levels may use well under i watt(often only fractions of a watt) of power.Some behemoth amplifiers don`t sound their best at these lower levels(nut some do pretty well).
Regards,

If we take the words "high sensitivity" to mean "high voltage sensitivity", then here is my suggestion: Look for "high sensitivity" combined with a low rated impedance, like 4 ohms or less, and preferably with a nasty-looking impedance curve (a deep dip, perhaps a peak in the midrange, maybe a severe phase angle). Chances are pretty good that such a speaker would work better on solid state amps than on tube amps.

Note that what I've really described here is a "high-sensitivity" speaker that is poorly-suited for tubes, which doesn't necessarily make it superior to a high-sensitivity speaker that works well with either tubes or solid state. Imo, ime, ymmv, etc.

Duke
dealer/manufacturer

Is it possible that high powered amps delivering 1 watt will sound worse than a lower powered amp delivering that watt? I would hazard to guess that the answer is yes. I've heard a few demonstrations of high powered amps vs. low powered amps from the same manufacturer, and often, the lower powered version sounded better where high power was not needed. Sure, a whole lot of other factors are not controlled and the design and components, etc. could be radically different between the two amps, so I am not drawing any hard conclusions. I know some solid state designers have gone to almost heroic extremes to minimize the number of output devices in their design because they claim that paralleling multiple devices degrade the sound. I have no idea if this is true, but, at least this is a plausible explanation of why some don't like the sound of high powered amps on high efficiency speakers.

As for the issue of high efficiency speakers that are difficult loads, I have found that compatibility with tube gear IS very much related to the difficulty of the load. A speaker, like some of the Wilson speakers, are surprisingly efficient (mid 90s), but none sound very good with most tube gear because they are difficult to drive. Other much less efficient speakers, e.g., Spendors, are MUCH more compatible with low-powered tube amps. I recently heard an old BBC monitor speaker (mid 80s efficiency rating, a 15 ohm nominal impedance) used with some quite low-powered pushpull amps (5 watts or so) and the combination sounded fantastic.

Larryi, in many cases you are correct, as I am guessing that Nvp also suspects.

Many high power amplifiers have a distortion characteristic that is actually higher at low power levels; depending on the amp the distortion might begin increasing at levels below 2-5 watts.

Due to the dynamic nature of music this 'first watt' is quite audible even on speakers of only moderate efficiency. For this reason to get that 'inner detail' that is often the 'magic' of a good system, it may well not be a great idea to put a high power amplifier on a high efficiency loudspeaker as the distortion might be higher rather than lower. The human hear translates many forms of distortion to tonality (odd orders are brightness and harshness, even orders contribute to warmth and lushness) and due to the ear's masking characteristic, distortion can obscure low level detail.

On higher efficiency speakers the distortion character in an amplifier that seems to be most successful is that where the distortion linearly decreases to unmeasurable as power is decreased. This is the realm of SETs, the Nelson First Watt designs and our own OTLs.

If the amp has this characteristic then it will likely work fine with a high efficiency speaker even if it has high power. Sorry if I am being a bit verbose.